Cursor display system

Abstract: The invention relates to a cursor display system adapted to cause a cursor 6 to move on a screen 1 in the same direction as that of a pointing device 2, such as a mouse, operated by an operator viewing the screen, even if the display on the screen is inverted, i.e. turned round through 180 degrees. To display the cursor 6, which is moved by operating the pointing device 2, on a display device 1 which is capable of inverting the display on the screen, a display status holding device 3 is provided for memorizing whether the screen displayed on the display device 1 is in a normal state or in the inverted state. The display status holding device is connected to a changeover device 4 for changing data of operating directions supplied from the pointing device 2 depending on the state memorized by the display status holding device 3. Further, a cursor position calculating device 5 calculates a display position of the cursor to be displayed on the screen, based on data supplied via the changeover device 4 from the pointing device 2 to supply the display position to the display device 1.

Description: This invention relates to a cursor display system, and more particularly to a cursor display system adapted to display a cursor on a screen in which a display is turned round through 180 degrees, in accordance with motion of a pointing device operated by an operator. Conventionally, when some explanation is made for customers, presentation is mainly performed by way of documents. However, with progress of electronization of information, an electronic presentation is more extensively performed, in which the explanation is made while viewing a screen provided by a computer. In the electronic presentation, a presenter or explainer operates the computer while viewing the screen. The same screen must be viewed by the customer. For example, when presentation is performed to the customer face to face by the use of a notebook-sized personal computer having a display device formed in one unit with a body thereof, the operator operates the computer to cause a desired screen to be displayed thereon, and then the personal computer is turned round for the customer to view the display screen. Further, there are types of computers adapted to permit the display device to be set horizontally for convenience of a face-to-face presentation. For example, there are a type whose display device and computer body including operator control elements can be opened flat, and a type having the display and the body already formed in one flat piece. Such constructions of the computer make it possible for both an operator and a customer to view the same display screen at a time. Further, it is also possible to turn the display screen round through 180 degrees for the customer to view contents of display with ease, whereby operation and explanation can be made without moving the computer body. On the other hand, recent application software more often uses a pointing device (coordinates-indicating device), such as a mouse, to point a particular portion displayed on the screen or to command an execution of a program. However, the use of such a pointing device in the above-described situation of face-to-face presentation causes the following inconveniences in operating the computer: The pointing device is constructed such that when the operator moves it forward away from him while viewing a screen in front of him, a cursor appearing on the screen moves upward, and when the operator moves it backward to him, the cursor moves downward on the screen. Similarly, when the pointing device is moved rightward or leftward, the cursor on the screen also moves rightward or leftward. Thus, the cursor appearing on the screen us moved in the same or analogous manner as the pointing device operated by the operator is moved. Therefore, in the face-to-face presentation, if the operator intends to use the pointing device after the display on the screen has been turned round 180 degrees for the customer to properly view the contents of display, the operator views the screen from the wrong or inverted side. Accordingly, the cursor displayed on the screen also moves in an inverted manner which is opposite to a manner of movement of the pointing device intended for the analogous movement of the cursor as usual by the operator. Therefore, the operability of the pointing device becomes very much degraded in such a case. International (PCT) patent application No. WO 91/00586A describes a system for reorientating stored images for display on a screen. Rotation of the screen is compensated for by determining a new scan origin location for the image, and accordingly re-ordering the stored image data so that the display image appears constant when displayed on a rotated screen. The apparatus transforms the logical coordinates dimensions of a display defined relative to the logical origin of a rotated screen to actual coordinates and dimensions relative to the actual scan origin of the screen so that the user does not need to compensate for the rotation of the screen. These actual coordinates and dimensions are provided to application software so that the rotation of the screen is transparent to the application software. Patent abstracts of Japan Volume 32, No. 499 (P/807) of 27 th December 1988, corresponding to JP 63 208 917A describes apparatus for inverting the direction of movement of an on-screen cursor which results from the direction of movement of a pointing device such as a mouse. As the mouse is moved, the cursor moves in a corresponding direction on an associated monitor screen. The mouse may be moved in an opposite direction whilst maintaining the same direction of movement of the cursor by activation of a switch. IBM Technical Disclosure Bulletin Volume 21, No. 7, December 1978, page 3024 and 3025 discloses a freestanding control unit for controlling the position of a cursor on a display screen. The control unit comprises two thumb wheels, one for controlling horizontal (left/right) movement, and the other for controlling vertical (up/down) movement. To accommodate both left and right handed users the unit may be turned over so as to position the horizontal thumb wheel by the users thumb. A gravity-controlled switch is incorporated in the unit to reverse the sense of the horizontal thumb wheel when the unit is turned over. It is the object of the invention to provide a cursor display system which improves the operability of a pointing device, such as a mouse, when the pointing device is used with a display turned round through 180 degrees. The invention is set forth in independent claims 1 and 4. Specific embodiments are recited in the dependent claims. To attain the above object, the present invention provides a cursor display system for displaying a cursor on a display screen adapted to permit turning of a display on the display screen through 180 degrees. The cursor display system comprises display means having a function of turning the display on the display screen through 180 degrees, a pointing device to be operated for moving a cursor appearing on the display screen, display status holding means for memorizing whether the display of the display means is in a normal status or in an inverted status in which the display on the display screen is turned round through 180 degrees, changeover means for inverting data of operating directions of the pointing device depending on the normal status or the inverted status memorized in the display status holding means, and cursor position calculating means for calculating a display position of the cursor to be displayed on the display screen, based on data delivered from the pointing device via the changeover means, and for supplying the display position of the cursor to the display means. The above and other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention by way of example. Fig. 1 is a diagrammatic illustrating principles of the invention; Fig. 2 is a diagram showing the whole arrangement of a cursor display system according to the invention; Fig. 3 is a table which is useful in explaining a manner of calculating a cursor position by means of cursor positing-calculating means; Fig. 4 is a flowchart of a control program for executing processing of cursor moving operations; Fig. 5 is a diagram showing an example of a screen display mechanism of the cursor display system of the present invention; Fig. 6 is a diagram showing another example of a screen display mechanism of the cursor display system of the present invention; Fig. 7 is a diagram showing an appearance of a notebook-sized personal computer incorporating the cursor display system according to the invention; and Fig. 8 is a diagram showing an example of hardware which implements the cursor display system according to the invention. First, there will be described an outline of an embodiment of the invention. Fig. 1 schematically shows the principle of a cursor display system according to the invention. In the figure, reference numeral 1 designates display means provided with a function of turning a display round through 180 degrees. When an operator normally uses the display means facing toward it, a screen is displayed in a normal state, whereas when the display means is shown to the other party positioned face to face with the operator, the display is displayed in an inverted state in which the dispaly is turned round through 180 degrees. Reference numeral 2 designates a pointing device, such as a mouse, a tablet, cursor keys, and a track ball, while reference numeral 3 designates display status holding means for memorizing whether a display of the display means 1 is in its normal state, or in its diametrically inverted state after a turn through 180 degrees. The display status holding means 3 is connected to changeover means 4 for inverting data of a cursor moving operation from the pointing device 2 in respect of the direction of the operation according to the state of the displayed screen memorized by the display status holding means. Further, cursor position calculating means 5 is provided between the display means 1 and the changeover means 4 for calculating a display position of the cursor on the screen based on the data of the cursor moving operation supplied from the pointing device 2 via the changeover means 4, and for supplying the same to the display means 1. According to this cursor display system, the display status holding means 3 retain whether the display on the display means 1 is in its normal state or in its diametrically inverted state, and controls the changeover means 4 according to the state of the display. More specifically, if the display is in the normal state, data from the pointing device 2 is supplied to the cursor position calculating means 5 with positive and negative signs attached thereto in a manner correspondent to directions of movement of the pointing device 2, whereas if the display is in the inverted state, the data from the pointing device 2 is supplied to the cursor position calculating means 5 with signs inverted or opposite to those attached when the displayed screen is in the normal state. Next, the embodiment of the invention will be described in detail. Fig. 2 shows the arrangement of the cursor display system according to the embodiment of the invention. Description will be made of a case where a mouse 2a is employed as the pointing device. The mouse 2a is equipped with a device for delivering a number of pulses commensurate with an amount of travel of the mouse 2a in longitudinal directions and a device for delivering a number of pulses commensurate with an amount of travel of the mouse 2a in transverse directions. Outputs from these devices are connected via changeover means 4a and 4b to an X coordinate counter 5a for calculating a cursor position in respect of a longitudinal direction and a Y coordinate counter 5b for calculating a cursor position in respect of a transverse direction to supply each of pulses, respectively. The X coordinate counter 5a and the Y coordinate counter 5b have their outputs connected to the display means 1 so as to display the cursor 6 at calculated X-Y coordinates. Further, the cursor display system 1 has the display status holding means 3 for holding whether the display on the screen is in the normal state or in the inverted state. The display status holding means 3 is connected to the changeover means 4a and 4b to control the same according to the state of the display. Assuming that the screen is displayed on the display means 1 in the normal state, and this state is held by the display status holding means 3, the changeover means 4a and 4b are in respective positions indicated by solid lines in Fig. 2. In this state, when the mouse 2a is moved rightward, for example, pulses delivered from the mouse 2a are counted by the X coordinate counter 5a to add to the present X coordinate, whereas when the mouse 2b is moved toward the operator, pulses delivered from the mouse 2b are counted by the Y coordinate counter 5b to add to the present Y coordinate. This is based on the fact that the origin of the X-Y coordinate system covering the screen is positioned at an upper left corner of the screen. Assuming that the screen is displayed on the display means 1 in the inverted state in which the display is turned round through 180 degrees, and this state is automatically or manually held by the display status holding means 3, the changeover means 4a, 4b are switched to positions indicated by the broken lines in Fig. 2. In this state, when the mouse 2a is moved rightward, for example, pulses delivered from the mouse 2a are counted by the X coordinate counter 5a to be subtracted from the present X coordinate, whereas when the mouse 2a is moved toward the operator, pulses delivered from the mouse 2b are counted by the Y coordinate counter 5b to be subtracted from the present Y coordinate point. That is, the position of the cursor in this status of the displayed screen is calculated with signs inverted from those of values counted in the normal display status of the screen. Fig. 3 shows a manner of calculation of the cursor position by means of cursor position calculating means. An updated position of the cursor resulting from a cursor moving operation by the operator is calculated as shown in Fig. 3 based on the present position which is indicated by the coordinates (x, y). More specifically, to move the mouse 2a upward in the normal display status of the screen, the Y coordinate is decreased by subtraction, whereas in the inverted display status of the screen, the Y coordinate is increased by addition. To move the cursor downward, calculations are made in a manner exactly opposite to the above-described manner of calculations made when the cursor 2a is moved upward. On the other hand, to move the cursor rightward in the normal display status of the screen, the X coordinate is increased by addition, whereas in the inverted display status of the screen, the X coordinate is decreased by subtraction. To move the cursor leftward, calculations are made in a manner exactly opposite to the above-described manner of calculations made when the cursor 2a is moved rightward. In this connection, it goes without saying that to move the cursor in an oblique direction, the addition or subtraction of the X coordinate value and the addition or subtraction of the Y coordinate value are performed simultaneously. Fig. 4 shows a flowchart of a control processing performed in a cursor moving operation. As shown in the figure, when data indicative of the cursor moving operation is input at a step S1, it is first determined at a step S2 whether or not the display on the screen is in the normal state or in the inverted state. If the display is in the normal state, determinations are made on whether the cursor moving operation (i.e. shifting of the pointing device) is directed upward (step S3), whether the same is directed downward (step S4), and whether the same is directed rightward or leftward (step S5). If the cursor moving operation is directed upward, the sign for indicating the direction of a longitudinal movement is set to - (minus) to thereby decrease the Y coordinate value at a step S6, whereas if the cursor moving operation is directed downward, the sign for indicating the direction of the longitudinal movement is set to + (plus) to thereby increase the Y coordinate value at a step S7. If the cursor moving operation is directed rightward, the sign for indicating the direction of a transverse movement is set to + (plus) to thereby increase the X coordinate value at a step S8, whereas if the cursor moving operation is directed leftward, the sign for indicating the direction of the transverse movement is set to - (minus) to thereby decrease the X coordinate value at a step S9. If the screen is in the inverted state, determinations are also made on whether the cursor moving operation is directed upward (step S10), whether the same is directed downward (step S11), and whether the same is directed rightward or leftward (step S12). If the cursor moving operation is directed upward, the sign for indicating the direction of the longitudinal movement is set to + (plus) to thereby increase the Y coordinate value at a step S13, whereas if the cursor is to be moved downward, the sign for indicating the direction of the longitudinal movement is set to - (minus) to thereby decrease the Y coordinate value at a step S14. If the cursor moving operations is directed rightward, the sign for indicating the direction of the transverse movement is set to - (minus) to thereby decrease the X coordinate value at a step S15, whereas if the cursor moving operation is directed leftward, the sign for indicating the direction of the transverse movement is set to + (plus) to thereby increase the X coordinate value at a step S16. Although the above control processing for moving the cursor is realized by software, this is not limitative, but the same can be realized by hardware. That is, the above control can be carried out by the use of switching means interposed in signal lines for transmitting information on the coordinates to move the cursor in a longitudinal and/or transverse direction. More specifically, signal lines having respective positive and negative polarities for transmitting pulse signals from the pointing device which are indicative of information on the orthogonal coordinates are physically or mechanically changed for connections inverted in respect of polarities, whereby pulses for calculation in inverted signs are supplied to the cursor position calculating means. Therefore, these switching means serve both as the display status holding means and as the changeover means. The switching means may be provided on the pointing device side or on the computer side. In addition, when the switching means is provided on the computer side, it is preferred that the switching means is responsive to a changeover operation for changing the display status of the screen on the display means. Fig. 5 shows an example of a screen display mechanism of the cursor display system according to the invention. In this example, the screen display mechanism is constructed such that in reading out display data stored in the screen information holding circuit 11 by a readout circuit 12, the display data is inverted in respect of the longitudinal and transverse directions, for display on a display device 10. In Fig. 5, outputs from the mouse 2a are connected to the X coordinate counter 5a and the Y coordinate counter 5b, and the outputs of these counters 5a and 5b are connected to an inverting circuit 13 and a changeover circuit 14. The inverting circuit 13 has its output connected to the changeover circuit 14, which is changed over between the normal display status and the inverted display status and held at the resulting status. The output of the changeover circuit 14 is connected to the screen information holding circuit 11. The screen information holding circuit 11 is formed by a video RAM (VRAM) in which display data is written. The screen information holding circuit 11 has its output connected via the readout circuit 12 to the display device 10. The readout circuit 12 is connected via a changeover circuit 15 and an inverting circuit 16 to a display control circuit 19 comprised of an X coordinate counter 17 and a Y coordinate counter 18, whereby the readout of the display data from the screen information holding circuit 11 is controlled. Further, the changeover circuit 14 has its output connected to a display data forming block 20. The display data forming block 20 is constructed such that it writes image data into the screen information holding circuit 11 at a location corresponding to coordinates indicated by the mouse 2a based on information on the coordinates of the cursor position. When the display data is displayed in the normal state on the display device 10, the changeover circuits 14 and 15 are in respective positions shown in the figure, in which the inverting circuits 13 and 16 are bypassed. Therefore, display information of the cursor is written into the screen information holding circuit 11 at a location normally corresponding to the coordinates delivered from the X coordinate counter 5a and the Y coordinate counter 5b. For example, when image data "ABC" is written into the screen information holding circuit 11 at a location corresponding to a coordinate position indicated by the mouse 2a, the display data forming block 20 delivers the X coordinate and the Y coordinate corresponding to the cursor coordinate information from the X coordinate counter 5a and the Y coordinate counter 5b as well as the image data. The image data is written into the screen information holding circuit 11 at a location i ndicated by these coordinates. The readout circuit 12 normally operates to sequentially read display data stored in the screen information holding circuit 11 in a normal manner under the control of the display control circuit 19 and delivers the same to the display device 10. When the display data is displayed in the inverted state on the display device 10, the changeover circuits 14 and 15 are changed over to receive outputs from the inverting circuits 13 and 16. The inverting circuits 13 and 16 invert the normal count values of the X coordinate counter and the Y coordinate counter. Now, description will be made, for example, of a case in which the maximum number of dots for display of the display device 10 is 640 x 480. Assuming that the coordinates indicated by the X coordinate counters 5a and 17 and the Y coordinate counters 5b and 18 in the normal display status are (x, y), the inverting circuits 13 and 16 invert the coordinates into (640 - x, 480 - y). As a result, data of the cursor is written into the screen information holding circuit 11 at a location inverted in respect of coordinates, whereas image data is written therein at a location normal in respect of coordinates. On the other hand, the readout circuit 12 reads data from the screen information holding circuit 11 in a manner inverted in respect of coordinates. As a result, data of the cursor is displayed on the display device 10 in its original normal or non-inverted state, whereas the image data other than the data of the cursor is displayed on the screen in a diametrically inverted state or in a position turned round through 180 degrees. Fig. 6 shows another example of the screen display mechanism of the invention. In this example, the screen display mechanism is constructed such that display data is written into the screen information holding circuit 11 after inverting the data in respect of the longitudinal and transverse directions, and the data stored therein is read out by the readout circuit 12 in a normal or non-inverted manner, for display on the display device 10. In Fig. 6, outputs form the mouse 2a are connected to the X coordinate counter 5a and the Y coordinate counter 5b, and the outputs of these counters 5a and 5b are connected to the screen information holding circuit 11. The output of the screen information holding circuit 11 is connected via the readout circuit 12 to the display device 10. The readout circuit 12 is connected to the display control circuit 19 comprised of the X coordinate counter 17 and the Y coordinate counter 18, whereby the readout of the display data from the screen information holding circuit 11 is controlled. Further, the outputs of the X coordinate counter 5a and the Y coordinate counter 5b are connected via the inverting circuit 14 and the changeover circuit 13 to the display data forming circuit 20. The display data forming circuit 20 delivers image data and an X coordinate and a Y coordinate indicative of the coordinates of the image data. The X coordinate and the Y coordinate are supplied via an inverting circuit 21 and changeover circuits 22 and 23 to the screen information holding circuit 11. The image data is written into the screen information holding circuit 11 at a location corresponding to these coordinates. When the display data is displayed in the normal state on the display device 10, the changeover circuits 14, 22 and 23 are in respective positions shown in the figure, in which the inverting circuits 13 and 21 are bypassed. Therefore, display information of the cursor is written into the screen information holding circuit 11 at a location normally corresponding to the coordinates delivered from the X coordinate counter 5a and the Y coordinate counter 5b. For example, when the image data "ABC" is written into the screen information holding circuit 11 at a location corresponding to the coordinates indicated by the mouse 2a, the display data forming block 20 delivers the X coordinate and the Y coordinate corresponding to the cursor coordinate information from the X coordinate counter 5a and the Y coordinate counter 5b as well as the image data. The image data is written into the screen information holding circuit 11 at a location corresponding to these coordinates. The readout circuit 12 normally operates to sequentially read display data stored in the screen information holding circuit 11 in a normal manner under the control of the display control circuit 19 and delivers the same to the display device 10. When the display data is displayed in the inverted state on the display device 10, the changeover circuits 14, 22, and 23 are changed over to receive outputs from the inverting circuits 13 and 21. As a result, although data of the cursor is written into the screen information holding circuit 11 in a normal state in which coordinates thereof are not inverted, image data is written therein in an inverted state in which coordinates thereof are inverted. On the other hand, the readout circuit 12 reads data from the screen information holding circuit 11 in a normal manner. As a result, data of the cursor is displayed on the display device 10 in its original normal or non-inverted state, whereas the image data is displayed on the display screen in a diametrically inverted state or in a position turned round through 180 degrees. Fig. 7 shows an appearance of the notebook-sized personal computer incorporating the cursor display system according to the invention. In this figure, the personal computer is comprised of a body 9 having a processor, a memory device, a keyboard, a display control circuit, and a floppy disc drive unit, etc. and a display device 10 formed e.g. by a liquid crystal display. A mouse 2a as a pointing device is connected to the body 9. The display device 10 is attached to the body 9 by a hinge mechanism such that the display device 10 is folded onto the body 9 when the computer is not used, whereas the display device 10 is opened through a desired angle to be temporarily held thereat when the computer is used. When an operator uses the computer face to face with a customer, the display device 10 is opened through 180 degrees, to thereby permit the display device 10 to be viewed by both the operator and the customer at the same time. Fig. 8 shows an example of hardware which implements the cursor display system according to the invention. In the figure, the processor 31 controls the overall operation of the personal computer. A read only memory (ROM) 32 stores a boot program, dictionary data, etc. In a main memory device (RAM) 33, not only an application program for electronic presentation is loaded, but also a program resides for displaying a cursor on a screen according to a moving operation of the pointing device. A graphic control circuit 34 converts screen information generated in the main memory 33 into a display signal, and delivers the same to the display device 35. The display device 35 displays image information of the application program including the cursor on the screen, based on the display signal delivered from the graphic control unit 34. A mouse 36 is used for moving the cursor displayed on the screen to indicate a figure displayed on the screen and the like for the customer, or to select an item from various kinds of menus displayed on the screen by clicking a button provided thereon. A keyboard 37 is used in inputting characters and numerical values required in operating the screen. A hard disk device 38 stores application programs for the electronic presentation and various data required therefor. A floppy disk drive unit 39 is used for driving a floppy disk to read therefrom or write therein various kinds of data related to the electronic presentation therein. As described heretofore, according to the invention, the cursor display system is constructed such that when a display on a screen is in a diametrically inverted state, the movement of a cursor on the screen is made similar or analogous in its direction to that of a pointing device, such as a mouse, operated by the operator. Therefore, there is provided an operating circumstance convenient to the operator in making a face-to-face presentation, with the display on the screen being turned round for the customer to view it. That is, when the operator operates the pointing device in a direction which is intended to move of the cursor displayed on the screen as viewed from the operator, the cursor is moved on the screen in the desired direction. This makes it possible for the operator to use the pointing device as usual without being conscious of an inverted display status in which the screen is turned round.

Claims: A cursor display system for displaying a cursor (6) on a display screen (1) and adapted to turn a display on the display screen through 180 degrees, including: display means (1); a pointing device (2) for moving a cursor (6) appearing on the display means (1); characterised in that there is provided a means for turning the display on the display means (1) through 180 degrees,comprising: display status holding means (3) for storing an indication of whether the display of the display means (1) is in a normal state or in an inverted state in which the display on the display means (1) is turned through 180 degrees in relation to the normal state. changeover means (4) for processing data from the pointing device (2) depending on the state stored in the display status holding means (3); and cursor position calculating means (5) for calculating a display position of the cursor (6) on the display means (1), based on data delivered from the pointing device (2) via the changeover means (4), and for supplying the display position of the cursor (6) to the display means (1). A cursor display system according to claim 1, in which the changeover means (4) is adapted to invert the sign of data from the pointing device (2) depending on the state of the display on the display means (1). A cursor display system according to claim 1 or 2, in which the display status holding means (3) and the changeover means (4) comprise switching means for inverting coordinates data supplied from the pointing device (2) in respect of longitudinal directions and transverse directions, and for delivering the data thus inverted. A method of turning a display on a display screen of a cursor display system through 180 degrees, the display system comprising a display screen (1), a pointing device (2), a display status holding means (3), changeover means (4) and cursor position calculating means (5); the method including the steps of; detecting whether the display is in a normal state or in an inverted state, 180 degrees from the normal state; storing the state of the display in the display status holding means (3); processing in the changeover means (4) data obtained by moving the pointing device (2) and inverting the data if the display is in the inverted state; calculating the cursor position in response to data received from the changeover means (4); and moving the cursor on the display means (1). A method according to claim 4 in which the step of processing the data in the changeover means includes the stages of determining in which direction the pointing device (2) is directed, and applying positive signs to downward and rightward movements of the pointing device (2) and negative signs to upward and leftward movements of the pointing device (2) when the display is in the normal state, and positive signs to upward and leftward movements and negative signs to downward and rightward movements when in the inverted state.

Inventors: OGAWA HIRONOBU, OGAWA, HIRONOBU, OGAWA, HIRONOBU, C/O FUJITSU LIMITED
Applicants: FUJITSU LTD, FUJITSU LIMITED
Application year: 1994
Main classification: G06F3
IPC codes: G06F3